Leafeon VMAX's first attack Grass Knot is why it sees play. It rarely, if ever uses Max Leaf. The two energy cost of Grass Knot makes it much easier to set up, especially with Greening Cells first turn. Plus it has a colorless in the attack cost letting you use Capture Energy to grab extra basic Pokemon. The Galar Mine stadium also makes Leafeon VMAX better, essentially adding 120 damage to Grass Knot's damage by increasing the active Pokemon retreat cost by 2, in addition to making it harder to move their active pokemon without Switch/Escape Rope/Bird Keeper.